All references cited in this specification, and their references, are incorporated by reference herein in their entirety where appropriate for teachings of additional or alternative details, features, and/or technical background.
Disclosed in the embodiments herein is an expandable chuck device for inserting into, holding and sealing a photographic imaging device during dip coating and drying operation.
Electrophotographic imaging members are known. Electrophotographic imaging members include photosensitive members, known as photoreceptors. Photosensitive members commonly utilized in electrophotographic (xerographic) processes may comprise, for example, a flexible belt or a structure such as a rigid drum.
Rigid electrophotographic imaging members, including drums or pipes, may be coated by many different techniques such as spray coating, immersion and dip coating. Dip coating is a coating method typically involving dipping a substrate in a coating solution, such as organic photoconductor coating, and taking up the substrate for the drying step. In dip coating, the coating thickness depends on the concentration of the coating material and the take-up speed (i.e., the speed of the substrate being lifted from the surface of the coating solution). It is known that the coating thickness generally increases with the coating material concentration or viscosity and with the take-up speed.
One method for dip coating electrophotographic cylinders, pipes or drums to form an organic photoconductor layer thereon comprises obtaining a drum having an outer surface to be coated, an inner surface wall defining a void, and an upper opening end and a lower opening end in communication with the void, immersing the drum in a flowing liquid coating material while maintaining the axis of the drum in a vertical orientation, maintaining the outer surface of the drum in a concentric relationship with the vertical interior wall of the cylindrical coating vessel while the drum is immersed in the coating material, the outer surface of the drum being radially spaced from the vertical interior wall of the cylindrical coating vessel, maintaining laminar flow motion of the coating material as it passes between the outer surface of the drum and the vertical interior wall of the vessel, and withdrawing the drum from the coating vessel.
An electrophotographic receptor drum may have the form of a relatively narrow cylinder or pipe. As coating of only the outside of a photoreceptor drum may be desired, in particular to avoid loss of the coating solution, a plug may be affixed at the top end of an electrophotographic drum before the immersion into the coating substance to prevent the coating substance from entering the void due to positive air pressure therein. A chuck member may be relied upon both to seal the top of the photoreceptor drum to prevent fluid from entering the opening in the drum by displacing air in the opening (i.e., the chuck member acting as a plug) and also carry it through this entire operation. The chuck may have a seamless plug shape to prevent the coating solutions from penetrating inside the drum by air leaking along the seam. The chuck device may be configured to have a stem portion anchored in the plug portion. The plug portion is inserted in the open top end of the photoreceptor drum and connected to a carrier assembly for transporting the photoreceptor through the coating and drying operation.
The use of a single rubber bladder for sealing the drum and for moving the drum from one process step to another has worked very well over the years but has the disadvantage of not allowing different diameters of photoreceptors to be coated using a single chuck. In fact, the solid or inflatable chuck system requires a specifically fitted single chuck for each of the different size diameter drums. As a consequence, multiple different diameter photoreceptors cannot be treated and transported through the same installation. As part of the task of coating different diameter photoreceptors, a plant operation may require that the individual chucks must be continually exchanged or “changed out”, commensurate with the size and number of the different photoreceptor tubes. Chucking devices used in production may use a compressed “doughnut” to perform these functions. Many new products being scoped for dip coating production have varying diameters (i.e., 24, 40, 60 mm). Of course, if there are, for example, 1200 chucks in each of say two dip coating production lines and three different drum diameters are scoped to be coated, changing over all of these chucks would not be a trivial matter. This complicated aspect of the operation of the coating/drying process can be very time-consuming as well as adding to the cost of such a facility by the requirement of a great number of differently sized chucks. Moreover, the single diameter chucks are expensive and require substantial downtime for change-over.
There is also a labor cost in changing chucks from one diameter to the next. There is also a material loss expected in changing out chucks due to incorrectly installed chucks resulting in the simultaneous loss of several photoreceptor drums and down time required for repair and recovery. When using single diameter chucks, every time a drum photoreceptor of a different diameter is coated, all of the chucks must be changed over to the new size. For example, chucking of a drum photoreceptor for coating involves gripping the pipe with sufficient forces to prevent movement, pull-off or rotation during processing. Chucking must seal the inner wall of the pipe to prevent solution from filling the interior. Chucks must also locate the pipe at a specific point and ensure the pipe is vertically plumb. All of these conditions frequently must be met in environments of solvent laden air, high temperature and humidity, and in a Class 100 clean-room.
A universal coating chuck would require no change-over or downtime. It is therefore one object of the present invention to develop a Universal Coating Chuck which uses a “bulb-type” gripping member. This bulb is molded in the larger diameter state, such that to reduce the chuck diameter for insertion into the inner diameter of the pipe, it needs to be pulled axially.